What is it about?
The book is, in a way, about two things. First, Dennett discusses (or, at times, introduces) quite generic 'tools of thinking' such as the familiar Occam's razor, and some litmus tests for detecting shabby arguments such as the 'surely test'. And second, Dennett discusses about some substantive domains of thought such as computers, consciousness and biological evolution.
Was it good?
Characteristically for Dennett, the book is enjoyable to read. Especially the relaxed and, at times, 'in your face' style of expression make the reading experience quite pleasant - and argumentation very accessible. To my taste, the first section - about the generic tools of thinking - remains somewhat disconnected from the rest of the book. Moreover, Dennett is in his element in discussing substantive matters such as consciousness and artificial intelligence, and therefore the book would have been just fine - and perhaps a bit more consistent as well - without the first section. Nonetheless, it is an absolute pleasure to follow argumentation of such a deep and no-nonsense-ish thinker as as Dennett.
The main take-away for me?
It's difficult to single out any particular take-away. Perhaps the main take-away is on a more abstract level. Namely, very clear thinking without the need of overly complex mental and rhetorical constructions can take one quite far (though only so far - the powers of 'mere' philosophy often run out when 'serious' science has still plenty of ammunition left). In particular, works like this makes one appreciate the method of the thought experiment as an often indispensable aid to clear thinking.
Who should read the book?
Well, anyone interested in philosophical (i.e. currently poorly understood) issues or the philosophical method is pretty much guaranteed to enjoy the book even if one would not fully subscribe to all Dennett's views and conclusions. For others, it may be that the subjects covered as well as the way they are covered may appear either overly fuzzy (e.g. the nature and origins of consciousness) or even a bit ridiculous (e.g. making a point with an example in which one is inside a robot having to control it by pressing unlabelled buttons while observing a wall of unlabelled lights as guidance).
Still, I very much would recommend this book - like any by Dennett - for anyone with a philosophical bent.
The book on Amazon.com: Intuition Pumps and Other Tools of Thinking